Abstract: Objective This study aimed at examining the expression of Beclin1 and LC3 in the skin of rat after contusive injury and at observing the process of autophagy in response to injury or trauma.Their significance in diagnosis of trauma and application in estimation of the post injury time interval were also investigated.Methods Immunohistochemistry and imaging analysis were used to examine the expression level of Beclin1 and LC3 at the injury site of the rat skin at different post-traumatic times.Results Expression of Beclin1 and LC3 in normal rat skin or immediately after injury maintained at a very low level,but their level started to elevate 6 hours after injury and showed increasing strong expression at post injury time of day 3,day 5 and day 7.Conclusion Over-expression of Beclin1 and LC3 as well as increased autophagy,a response to injury,can be observed in the rat skin at the injury site.The expression level of Beclin1 and LC3 starts to increase 6 hours and shows a linear increase up to 7 days after injury.Beclin1 and LC3 may serve as a marker for estimation of the post injury time interval.

Key words: contusion, autophagy, Beclin1, LC3, immunohistochemistry